Earlier quoted context omitted.
Because a prophylactic means taking it regularly in order to avoid catching it, with the implication of the poster’s statement being that ivermectin, which carries significant risks when taken by a human at various doses, was the cause of the person going to ICU
Exactly. Just because someone doesn't dose something correctly, doesn't mean there is necessarily anything wrong with it. Shall we ban water? Sometimes people don't dose that correctly either, and drown. What a dangerous substance!
Let’s take vaccines. Covid itself has a risk of harm of around 1:100 for older age groups of requiring hospitalisation. Risk of harm for vaccines is established at around 1:200,000.
Ivermectin? There is no good data on the therapeutic index however it is a toxic substance with a low therapeutic index and a narrow therapeutic window.
The sensible thing given the available data is to encourage vaccination. Barring that, masks and social distancing. And of course there are places where both there is no vaccine supply, and social distancing is economically in feasible. Is this a use case for ivermectin? Most data says no because establishing TI and TW and ensuring adequate safety of dosing is logistically about as difficult as maintaining social distancing.
Good chat